. Author manuscript; available in PMC: 2014 May 1.

Published in final edited form as: JAMA Neurol. 2013 May 1;70(5):587–593. doi: 10.1001/jamaneurol.2013.2334

Table 2.

Sleep measures and nap characteristics

Variable	All N = 142	Aβ42 >500 pg/ml N = 110	Aβ42 ≤500 pg/ml N = 32	95% confidence interval of group differences
Sleep Efficiency (%)	82.9 (6.2)	83.7 (5.6)	80.4 (7.7)	(0.8, 5.7)
WASO (minutes)	56.1 (22.6)	54.0 (21.8)	63.1 (23.9)	(-17.9, -0.21)
Total sleep time (minutes)	402.6 (44.6)	403.0 (47.3)	401.3 (49.0)	(-16.0, 19.5)
Time in bed (minutes)	486.4 (49.8)	482.3 (47.3)	500.6 (55.8)	(-37.9, 1.23)
Nap days per week^a	1.4 (1.7)	1.3 (1.6)	1.9 (1.9)	(-1.3, 0.1)
Frequent Naps ≥3 days per week (number (%))	26 (18.4%)^a	16 (14.7%)^a	10 (31.2%)	(-0.32, -0.01)

All data show mean (SD) unless otherwise stated.

One participant was missing sleep diary nap data.